Liquid helium level regulation improvement in the LHC electrical distribution feedboxes

Abstract An important cryogenic equipment of the Large Hadron Collider (LHC) consists in electrical distribution feedboxes (DFBs) which are used to power superconducting magnets accelerator. These contain current leads achieving transition between copper cables at ambient temperature Niobium-Titanium wires temperature, immersed a liquid helium bath 4.5 K. This must be regulated defined level allow powering LHC, and this regulation often caused non-availabilities past. paper presents development new control scheme, coupled existing PID controller, significantly improving regulation, rejecting disturbances highly efficient manner. First, dynamic model DFBs was developed EcosimPro software using CRYOLIB library reproduce simulation issues. In second step, proposed modes were tested validated simulation. Finally, will present results obtained 2021 on real operation validating approach prior its massive deployment all around LHC cryogenics.